The present invention relates to a guide template for a sewing machine moving along its contour by means of a driven roller, to sew workpieces of different form and/or size. The template has a number of sections which can be moved relative to each other.
It is the purpose of the present invention to limit the number of guide templates required in contour sewing machines for moving the workpiece relative to the stitch plate for sewing workpieces of different size and/or shape to a small number.
With a guide template known from U.S. Pat. No. 3,216,380 of the above type, there is a number of overlapping template sections which are moved by means of a spindle and a handwheel lengthwise relative to one another, in order to produce workpieces of the same shape, but different length, avoiding the interchange of templates; with one seam according to the contour of the control template.
Similar control templates are discussed in a sewing device, having a rotary table and described in U.S. Pat. No. 3,407,759. With this known arrangement, guide templates located at the periphery, having several sections and overlapping in two planes may be reset for this magnetic roller travelling along it by means of a central adjusting device for workpieces of different length, but identical shape.
While these known guide templates can be adjusted only for workpieces of different lengths, U.S. Pat. No. 3,433,091 describes a template where only the shape can be varied. This comprises a rigid support and a large number of slot bolts movable for adjustment in one or two rows and located close to one another in the support, with the heads of the bolts forming the running surface for the roller.
U.S. Pat. No. 3,774,558 describes an adjustable template for use in a sewing device used for sewing of workpieces of different shape and different sizes. It has two base plates which can be moved relative to each other and on which a large number of segments with oblong holes can be moved and set. They have face surface ends abutting without steps to form an uninterrupted track for a magnetic roller. While the shape adjustment can be made of shifting the segments which taper rearward starting with the face surface, a rail connecting the segments on each of the movable base plates makes possible the setting for the various lengths.
With these known guide templates, a change in shape and even a change in shape and length is possible. However, both designs require a longer change-over period because of the cumbersome adjustment of the bolts and the shifting of the segments; therefore they are suitable mainly for sewing arrangements where there is no frequent change of the workpiece shape, as for example, in the making of cuffs or collars for shirts. In addition, the desired shape can be adjusted without the use of an adjustment template adapted to the seam contour.
High-grade garments, e.g., men's formal jackets, are produced in a large variety of standard sizes, retaining the basic shape, with the various sizes occurring in rather large numbers. The overall appearance of a jacket depends mainly on the shape of the lapels of the two front sections. The sewing of the lapels along the edges of the front section requires a skilled worker.
It is, therefore, an object of the present invention to provide a guide template of the above type which makes it possible, while maintaining a fixed shape of a garment, for an unskilled worker to adjust without much loss of time, these parts of the template to any size of the garment in any sequence so that there is obtained the guide template required for a certain workpiece size for determining the seam contour.
Another object of the present invention is to provide an arrangement, of the foregoing character, which is substantially simple in construction and may be economically fabricated.
A further object of the present invention is to provide an arrangement, as described, which may be easily maintained in service and which has a substantially long operating life.